The invention relates to systems and methods for determining the quality or concentration of a water based fluid and/or the depth of the fluid within a tank. Specifically, the invention relates to systems and methods for determining the quality and concentration of diesel exhaust fluid (DEF) contained within a tank and/or the depth of the DEF within the tank.
DEF is used to reduce nitrous oxide (NOx) gases in the exhaust of diesel engines. DEF is a mixture of purified water and 32.5% automotive grade UREA that is injected into the exhaust as a mist. The mist mixes with the exhaust and breaks down NOx in the exhaust into nitrogen, water, and carbon dioxide. When contaminants such as diesel fuel, water, ethylene glycol, etc. mix with the DEF, the ability of the DEF to reduce the NOx in the exhaust is diminished and/or irreversible damage may occur to the NOx reductant system.
DEF is stored in a tank of a vehicle and is injected into the exhaust at a ratio of about 1:50 to the diesel fuel being burned. A level of DEF in the tank is determined so as to provide an indication to a user when there is a need to add additional DEF.